Pump



April 13 192s.

'P. GHIARDI 7 run Filed Oct. 27, 1925 2 Sheetg-Sheet 1 April 13, 1926. 1,580,131

.P- GHIARDI rum Filed Oct. 27, 925

2.9 29 as a 2 Sheets-Sheet 2 iPatented Apr. 13, 1926.

-' means for operating the same.

UNITED STATES A 1,580,131 PATENT OFFICE.-

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Application filed October 27, 1925. Serial No. 65,241.

To all whom it may concern:

, Be it known that 1, PETER Gmanm, a citizen of Italy,'residing at Kittanning, in the county of Armstrong and State of Pennsylvania, have invented certain new and useful Improvements in Pumps, of which the follmving 1s a specification, reference being had to the accompanying drawings.

, This invent-ion relates to pumps and more particularly to a high pressure pump and An important object of the invention is to provide a novel and readily producible structed in accordance structure in such operating mechanism whereby the piston of the pump may be caused to reciprocate.

A further and more specific object of the invention is to provide an operating mechanism for reciprocating the pistons of that type of pump wherein the piston is advanced longitudinally of the pump shaft by a worm formed upon the pump shaft, the piston being in the form of anut.

and construction shown in the accompanying drawings, wherein for the purpose of illustration is shown a' preferred embodiment .of my invention and whreina- Figure 1 is a. plan: view ,of a

pump con- Figure 2--2 of Figure 1;

Figure 3 is a sectional view .through the umpv p Figilre 4 is an enlarged detail sectional view through the; drive shaft;

an arged detail sectional Figure 5 is the manner of preventing ro view showing 'tation of the piston of the pum Figure 6 is a perspective view of one of .the piston sections.

Referring nowr more pa icularly to the drawings, the numeral 10 indicates -a pain cylinder having the usual valves 11 contro ling the intake 'and discharge therefrom. Rotatably mounted at the axis of the cylinder is a worm shaft 12 andmounted upon this shaft is a piston 13 formed as a nut and held against rot tion with relation to the cylinder by means of a grooveli formed in the cylinder wall and engaging with a lug 15 formed in the periphery of the p18- ton. As a means for packing 'topreven leakage about the worm shaft 12, I have shown a plurality of telescopicall engaged sleeves 16 surrounding this she at each other objects I attain by the with my invention; 2 is a sectional view on the line ion 27..

extensions 32 at each side of the piston 13, one of these'sleeves at each side of .the piston being secured to the cylinder wallwhile another of the sleeves is shown as attached to the piston. sleeves are' so constructed that each sleeve interlocks with the next preceding sleeve and forms a tight joint therewith so that as the sleeves are ext-ended, the shaft is covered by the extensible tube thus formed,

which tube has its ends sealed to the piston.

and cylinder.

The operating mechanisntfor the pump includes a shaft 17 secured to the worm shaft 12 and axially aligning therewith, the shaft being journaled in a casing 18 and having rotatably mounted thereon within the casing a .pair of pinions 19. Each pinion 19 has projecting from the face thereof next adjacent the other pinion a lug 20- adapted The for coaction with a key 21 carried by and depressible with relation to-the shaft 17 so that it may yield gear being engaged therewith does not happen to properly .align when the gear is moved 'nto its engaging position. The gears in event the lug 20, of the 19 are continually 111 mesh with teethat opposite sides of acrown gear 22, which crown gear may be rotated in any suitable manner as, for example,

The ends with a shifting collar 24, these collars being engaged by forks 25 secured to a rack bar '26, the teeth of which mesh with a pin- Atits opposite side, the pinion 27 meshes with a second rack bar 28. Eachv rack bar 26 and 28 has an extension .29 pro" vided with a beveled end 30, the purpose of I which will presently appear.

provided or maintaining the rack 'bars against accidental movement and for malntaining them in their adjusted ositions.

A Spring 31 is,

The shaft 17 islikewise provi ed with an i 7 t Upon this bar 33 are formed a. pair of spaced cam blocks 37 for coaction with the beveled ends 30 of the extensions 29 of the rack bars 26 and 28.

'pted to selectively receive the springs 35-. ha

from a; motor 23. 3

ars 19 are each formed at their outer I t-udinally in one direction. When a gear 19 gaged by the cam and the rack bar moved is in engaged position, one of the extensions 29 of the rack bars projects into' the path of the cams 36. When the bar isshifted a pre- ,r determined distance and the piston 13 is completely straddled toward one end of the cylinder, this projecting extension is en longitudinally, shifting the gears, causing the other gear 19 to come in looking engage ment with the key .and the other of the extensions 29 to extend into thepath of the cam. This causes a reversal of the direction ofrotation of the shaft 17 and accordingly a reversal ofthedirection of operation of the bar 33 so that the second cam surface 7 is brought into engagement with the newly projected extension 29.

While I do not wish-to be limited to any particular form of piston 13, 1 preferably make the body of thepiston of less diameter than the'interior of the cylinder 10 and dispose on each side of the body of the piston the plates 38, these plates being circular in form and having the outstanding lug 15 which engages in the groove 14 formed in the barrel or cylinder 10. These plates '38- are held against opposite faces of the body of the piston by means of headed screws 39 or like means. Disposed between the perim eter of the body of the piston and the cylinder is a'packing ring 40, this packing ring being Held in place on each side by the annular plates 38. Preferably the body,13 of the "piston is formed in two halves and the annular plates 38 act as rings holding these two halves together and holding the packing in place and holding the innermost of the telescopically engaged sleeves 16 in position and fast to the annular plate 38. This con struction permits the ready assembly of the two sections of the piston and thefholding of these two sections in place by the plates threaded, the piston being formed in two half sections having a circular passageway having interior screw-threads operatively engaging with the screw-threads of the shaft, the body of the piston being of less diameter than the interior diameter of the cylinder, annular plates disposed on each side of the body of the piston, the two sections of the piston having laterally projecting'flanges with which said annular plates engage to hold the end sections in position, a packing ring extendin around the perimeter of the piston and iaringagainst the cylinder wall, means holding the plates to 5 the body of the piston, and coacting. means formed upon the plates and the cylinder'to prevent rotation of the piston. 2. In a mechanism of the character'described, a pump cylinder, a piston reciprocablethereinfa shaft extending longitudinal-' 'ly of the cylinder and exteriorly screwthreaded, the piston being formed in two half sections adapted to be assembled about therod and providing an, opening having screw-threads for coactioh with the screw threads of-the rod and coacting means'oarried by the piston and the wal lj of the cyl inder for preventing rotation of the piston. In testimony whereof I hereunto aflix my signature. 7 a o PETER GHIARDI. 

